The muscle of your off grid system
People often wonder what the most important part of the solar off grid system is. The natural assumption is that it’s the solar panels themselves. But that fact is that your batteries are the muscle behind your system. Without them you’d have a great way to power your house during daylight hours and nothing else. And during daylight is probably when you use the LEAST amount of electricity!
Batteries come in every shape and size, but it’s the type that is the most important when working with solar and wind power. Most people assume that you can just hook up a car battery and away you go, but this is 100% WRONG. You need to have deep cycle batteries for a solar power system. Deep cycle batteries are what you usually find in a boat or RV.
You see, a car battery is designed for short bursts of large amounts of energy. Think about your car: it needs about 2-3 seconds of power, at a couple hundred amps, and then it’s quickly recharged by the alternator. The solar battery works differently though. It usually has lower amperage draws out of the system, but they draw for much longer. And the solar and wind power that feeds into them is often slower and steadier. So there are different batteries for different applications.
I am often asked how many batteries most people need to store energy for their home. Most off grid homes have 16 batteries, in a 4 x4 wiring arrangement, 4 in series and then 4 rows wired together. The amperage will vary depending on your consumption, but the batteries are usually around 400 amp-hours. If you remember your series and parallel wiring math, that means most off grid homes have around 1600 amp hours of capacity.
Another issue that comes up is expense; people want to know just how much they cost. Batteries are not cheap but I’ve found a neat way to cut down on those costs. This sneaky little method will save you thousands on solar batteries, car batteries and the like. It’s a way you can do it yourself, save a bunch of money and learn a neat new skill.
Batteries are also the part of the system that need the most maintenance (although it’s still not much). Twice a year I spend about 3 hours cleaning the corrosion off the connections, adding distilled water, tightening bolts, and cleaning up the battery storage area. It’s time well spent, as the better condition the batteries are in the more likely it is that they’ll last 10 years and more (which I have found to be common in well cared for batteries).
The final issue to consider with batteries is where to store them. For most climates you can store them in an out building or a shed. You would ideally have them inside a chest or cabinet inside the shed. It’s preferable not to have them in your home because they do off gas. Regardless of where they are they need good ventilation. Temperature for batteries is important, and the closer to 50 degrees you can get them the better. When batteries are cold, their performance goes down, but their life span goes up. For hot temperatures it’s just the opposite.
Hit me up with your comments and questions below.
Yes, Mr. Bates you are absolutely right. The Batteries are your lifeline and the whole reason for the PV’s. I did OK however. I live in an apartment, so I cannot go off grid all the way, so I created an emergency system using two 100 watt mono panels. I now have two “Interstate” 29M 105 Ampere Hour Deep Cycle Batteries for a total of 210 Ampere Hours. The panels charge these quickly and since they are mono pasnels they are not affected by the glass the sun must pass through to activate them. Coupled with a 1000 watt pure sine wave Inverter…I have a decent Emergency system…I believe. Already purchased the Battery Charger so I am getting ready to pack everything up in their Faraday Boxes and just charge the Batterires every month. OT a quick Heavy Charge, but a slow Deep Trickle Automatic Charge.
Hi from Torino Italy.
FamilySolar
Where is the best place to buy solar panel components in regards to price and quality ?
We need to put our batteries underground about four feet down were it’s 50 degrees at all times in some kind of vault so access is available
YES,,,AND INTEGRATING IT INTO A STORM/ROOT/WINE CELLAR IS IDEAL.
Just got a Lennox solar assisted system that powers the system during day and when system not in use sends excess power to house. Seems to be working well. Company also tracks power output and I can check it anytime on the web. Going to add rest of panels and go off grid. Not cheap, but alot less than some I’ve seen mentioned here.
In 2009 I had a 4.3 KW PV system installed on my Florida roof for $$32,500. Government credits covered $17,619 of this, or over half. The problem is that it is linked to the grid and when the grid is down, it is down. Now I want to add the components, inverter and battery bank, that will make it independent of the grid when I wish. The company that put it in wants about $10K to do this and says my warranty will be voided if I open the inverter box. I’m looking into intercepting the line into their inverter to enable alternate connection to a new inverter-battery bank.
There is new technology in batteries and I wish to get the latest design (like glass-mat?).
What is best in the very near future? I wish to buy before the dollar crashes.
Bob, I’m pissed off just hearing that story! For that kinda cash, you’re system should’ve been set up for both methods anyhow & Id look at the electronics warranties & the company warranties! So you can see how bad the company is screwing you into being stuck with them. Idid heating A/C for 25 years & know all the “BS” rippoff tricks for warranties. A good electrician can handle this. “Make SURE he puts in-line FUSES EVERYWHERE! Before Every Electrical Device or component that’s added to protect EACH &
Every Device separately. Same thing should be setup for all your solar arrays on the roof, too!?? Fuses aren’t high priced & are safety devices but just the way this company acts, I’ll bet they didn’t protect things right so they could hit ya for $$$ lots! Some A/C Companies do it too so I’ve seen it….I would NEVER do that but When I found their crappy work, I’d do it right & have satisfied customer for life. No need to screw customers to make money & I’d have my system looked at & make sure it’s done per the
manufacture’s spec’s. county codes(& if they pulled the proper permits, both state & county+city) then an
electrician writes it up, for better or worse but if this company cut corners(I’ll bet they did) you can get some cash back…I would!! Good luch & don’t lay down. you need this right& to work!!! peace
I use deep cycle batteries that are made for electric fork lifts. I never let them go below 50% and charge them with a Kubota 7KW diesel generator while running my house also.
You didn’t mention anything of controllers. Are ordinary auto batteries an acceptable choice?
Absolutely bad.
Where is the cheapest place to buy a good battery.
David, man you just asked the question that I’ve been dying to give out an answer to. How would you like to purchase a 105 Ampere Hour Battery for $150.00? That’s a $300.00 Battery you know? Here is what it is: Manufactured by “Interstate” and weighs 65 pounds if that gives you any idea of the thickness of the “Plates”. It is a Monster Series 29M Deep Cycle Marine Battery with both kinds of terminals on it. which is perfect. It is Sealed Lead Acid and fairly good sized, about 15 inches long. Instead of buying those cheap Battery Boxes, I bought two Coleman Coolers with wheels to be able to move these wo batteries around without breaking my back plus I mounted my controller on the outside of one of the coolers ANYWAY, HERE IS HOW YOU GET THE BATTERY FOR ABOUT HALF PRICE. FIND OUT THROUGH SOMEONE AT THE PLACE WHERE YOU GET YOUR CAR REPAIRED WHERE THEIR WAREHOUSE IS LOCATED. You may have to tip one of the mechanics…you have to figure out the best way to get the info. Once you get the info, throw an old worn-out battery in your trunk for exchange(save 10 bucks). Dress in bluejeans and an old shirt and show up at the warehouse office and tell them what you want to “pick-up” and that you were told that they were the BEST and you brought an exchange. Keep it Low-Key and don’t be nervous…these guys normally want to help people out if they can and some big wheel is not leaning over their shoulder. Believe me, if you walk in there with the old battery in hand…they are going to help you out and you will save yourself about $150.00 and GRIN all the way home. TAKE CASH just in case you need to tip the guy who has to lug this monster to your trunk. Mind-you, this is not illegal…just Wholesale. They will probably make up a receipt using your name or “other”, but not to worry. There is where you can get your battery!!! WHAT A DEAL!!!!!!! Happy hunting.
Alternately, you can buy a well reviewed 105ah AGM deep cycle 12v Duracell battery at a Sam’s Club for about $175. These are very good batteries for the price.
Do take a ‘core charge’ exchange battery, virtually any junk car battery, to save an additional $18.
I’ve been visiting my local golf cart store and getting used batteries to recondition at $20-30 each. These are 6V Trojan batteries and are coming back very well. I invested in a good smart charger that has 7 phases. This takes care of the sulfation that might be present. I also use a chemical mix to help in the process. They may not last 10 years but the overall return is well worth the effort to restore them.
What about gel ceel and AGM (deep cycle) batteries. Seems ro me tese would be logical battery in this application.Can they be refurbished??
2 Questions:
1. I am curious about the potential problems of an EMP. Specifically, what will happen to my batteries if such a thing happens?
2. Fire risk or problems of storage in a wood container?
EMPs only affect solid state electronics (as a high current pulse burn out and fuses components on the chips). Batteries would be unaffected.
Charge less for the book and sell more. I won’t pay $50 for a DIY book. Also, don’t believe they are the only ones that know how to recondition a battery properly. A little arrogant on their part I believe. Like most of your guidance but not this one.
I checked with Edison Iron on their batteries. Can run them down to 5% and it’s OK. Nickle Iron batteries sound like a good deal for a solar system. Now the price is a bit high. They quoted me a 600 AH battery 12 volt for $5,400.00 and that is pricy. They are a 20 year battery.
Anyone have an experience with Edison Iron batteries?
I enjoy reading your articles, I am slowly building the neccessary tools and knowledge to try and survive. i often watch the survivalist shows on TV, I don’t think they are crazy, I wish I was as far into it as they are. Over the past 5 years I have lost all trust in our government to take care of anybody but themselves. That seems ironic for someone that spent 20 years active duty and an additional 24 years as a civilian government worker. I wish I could retire now and start seriously building my survival home, but that will not happen for another three years, I pray our society will last at least another 4 to 5 years. I am armed, I have accomplished that part, but I know like you say that will not keep me alive for the long term. Anyway, keep the info and lessons coming, I don’t have them memorized but I do have them handy for when I need them.
Would it be any more of a benefit to use gel batteries?
The batteries are the most important part of your off grid system.
I use surrettes . They are also called rolls . The ones I have weigh
300 lbs each and cost 1000.00 each. But they will last up to 20 years
if they are cared for . They need to be watered , and equalized to be
kept in great shape. If on a solar system you are also using a inverter
and most likely a diesel generater . The brain of the system is the inverter
Which tells all the components of your system when to and what
to do. Anyway the rolls are expensive but last the longest.
Would the batteries be drained ever or is it ok to leave continually charging even if you’re not using them much
Thank you Frank for the DVD. I just got it and have not viewed it yet. Need a dvd player. BUT I will spend a lot of time with it. I have some Iraqi Dinar which will revalue probably this week. If any of my fellow Patriots want to make some money fast buy some this week. You WILL have enough to build a great system. And I will have enough to buy a DVD player!! I like the advice about the Marine batteries. I did hear that they were the best to buy. Can’t wait to start building it…Shellie, retired Army- Walter Reed.
Well Shelley, as a fellow Dinarian I sure hope your right about this week. {you must know we’ve been hearing “this Week” every week… for past 5-10yrs!}
Currently, It does appear that we are looking @ a Global Currency Revaluation coming as of July 1st, 2014.
The offset is the Dollar will loose some ground in this process. We’ll just have to wait and see.
On the Solar topic, I just purchased a quality ZAMP 80w panel package for my RV, and off grid Mtn camp.
I hope to illuminate the woods around my camp at night and have a charge source for the house battery in the camper as well. Although only an 80watt portable charging unit, its a very complete and simple setup. To go with the ZAMP solar panels, I chose to purchase 2 ” VMAX” tanks SLR100 AGM sealed Glass mat batteries. {100amp hrs each} According to VMAX they have a 25yr shelf life. {Of course that’s dependent of frequency of use and drain} Overall, I spent $750.00 to “Let there Be Light” and some useable stored power whenever needed. Overall, I’m very pleased with the simplicity and quality of the products I purchased. RVers are well aware of the quality of ZAMP products, and VMAXTANK’s should be a good match as well.
PS. HEADSUP! I just wanted to add that there is a NEW far superior solar material coming to market soon. I’ve read recent reports thru Stock Investment sites. That’s GREAT NEWS 4 us and the planet! a BIG breakthrough in solar collection coming, watch for it.
Never heard of tow motor batteries but sounds powerful.
I use 420 AH Interstate deep cycle batteries. They are 6 volt so I have to series them. Have 16 of them now and will be adding 10 more soon for a total of 5460 amp hours of power @ 12 volts. I have been paying $273 for 2 batteries @ Interstate with no trade-ins. This in south east Texas.
I put safety can (sea train container locks) on my equipment house. Found out Master keys those locks alike ?????!!! I bought American locks that are keyed differently :)
paul i live about 60 miles south of you,,,, i get tow motor batteries from your local napa store,,,, i live nears mansfield ohio and N A P A stores all over ohio
i use tow motor batteries,,, there a little over 200 each but the ones i buy have lots of lead plates,,, cranking amps are 1400,,, each battery,,, and the tow motor batteries are deep cycle as tow motors are charged over night slowly just like solar and turbines,,, at least i think thats the way to go,,, little more expenseive but i think its worth it,,, so far i have 12 of these batteries.
I sent you a email just recentally about , will the suns solar flares affect our solar systems if it comes too close?.
F.Y.I. Here in the desert Southest the time we need the most power is durng the day as our summer temps get over 100 degrees and cool down somwhat in the night.
Aloha Frank,
I watched the entire “Off The Grid” video that Chris made of his home in Colorado. I was very impressed and believe that everyone here should take notes while watching this video. Chris names what parts he used and how he installed these components.
I test,tune,evaluate and photograph Wind Turbine prototypes for different companies and of course, I’m completely “off the grid” in a much different way than Chris has done because I did the research and built my dual PV system before I watched the video that Chris made some time ago.
You don’t have to take my word for it, but I can tell you that the average electricity bill in Hawaii is between $250-$350 a month and you can do the math. I’ve had my system up and running for two years now for completely different reasons and I will tell you that six tsunamis in three years is one heck of a motivator to be completely “off the grid” in order to provide emergency communications during disasters such as tsunamis and hurricanes but don’t wait for a disaster to get you thinking and interested in getting yourself “Off The Grid”, watch the video and take good notes. The system that Chris built for himself can be done for less than $10K and you’d get a return of your $$$ in less than 5 years. Thanks Frank for offering this video,it’s worth every penny! Mahalo- Todd Honolulu,Hawaii
I was under the impression one needed batteries that cost several hundred of dollars each but you are talking about using a regular deep cycle batteries that cost, what a little more than hundred?
You are correct, Gordon. You will need several, but you can use regular old marine batteries.
Frank,
Thanks for all your insight and technical advice. As I am a Marine Engineer (retired) I know what it takes to do what you do.
I have yet to build my first panel. I have been reviewing the info I purchased from you but not as hard as I would like.
I am renovating my circa 1830 barn (LINY) I am currently living in with my family and plan on going solar. Money is an issue when it comes to this so I have been very slow in the start up.
I just wanted to say thanks for all the time you put into helping us all get ahead of the curve.
This is a necessity. Not a luxury. We all need to do this. I will keep you posted on my progress.
Why don’t you start a tech program for people who would be willing pay to learn how to build (hands on) I would come and be a student again. And then be more comfortable with all solar related systems.
John
I must store my batteries inside a steel building. Inside this steel building I have built a small apartment style living quarters. Although the batteries aren’t actually inside where I live, they are in a area where I spend a fair amount of time. Because of this I feel that sealed batteries are my best choice. Winters can be very cold here, so a fairly stable temperature environment would make my batteries last longer. Any thoughts ?
Tracy
Another tip to help with battery longevity is to NEVER discharge below 50%
good tip,but I have go-cart batteries 6v hooked in series([email protected] time)for 12 volts.this doubles your ahrs.then connect your parallels..youll also need a deep cell batt charger!!not a standard car battery charger,also,charge at 2ah setting ,for the initial charge(you should start with fully charged batts),higher charging/quick will reduce your batts life!!good luck,,
I live close to Toledo Ohio would like to know where I could purchase them thanks
I am working up a solar PV system design and have a question about the module short circuit current. This appears to be a constant of 5.34 on the Bonus Solar Sizing Worksheet, and I want to know what this factor means and how that works in the calculations for PV array sizing. It seems to impact the PV controller size, but that is not clear.
Please explain or elaborate on the module short circuit current factor.
Do keep those batteries cool, very important. I am doing double walled enclosure heavily insulated with a small dc vent fan drawing cool air thru an underground pipe with screened intake. Screened vent @ upper part of enclosure. This arrangement assures discharge of gas as well as hot air if the fan stops working. A steel frame with heavy wood cabinet extra tall to keep battery level cooler and it is in shade most of the day. Also a secondary roof about 3″ above the first one to shade it and allow air flow. I have designed cabinets like that for the electric company and they work very well.
Schedule 40 PVC conduit for wire into & exit. Side doors for practical entrance & work. Good locks are a must. Abus are good and hard to cut plus very affordable.
Iam trying to decide if I should generate elect. power by solar or wind. We do live in a windy area so which dom U think would be the way to go???? I think I like the idea of wind. THANKS
I like what your your doing Frank. The solar panel and wind turbine dvds, cool and would love to meet you some day.
I would like to see some like minded folks get together and build some systems and put them in some homes for families that want this life style but need help.
In return for the help they will agree to provide labor and
some money from their savings to provide systems for families that were in the same situation they were in before they had their system.
Frank, I think this could be a great thing for mother earth, our economy.
My wife is Native American and she has me tuned in with nature, I’m studying to be an herbalist now at 51 years old, retired after serving 27 years in the United States Army.
Frank, what do you think about my idea? is it possible? am I crazy?
I would love to hear your ideas
Ross A Boger
ps if you don’t read what i have to say then i wounder why. i want you to read my idea and i need your feed back. I sent an email response to the email you sent me. I recieved an auto responder saying you were to busy to reply but go to your blog and maybe someone else may answer my question.
you took my money fast, did’nt send me to a blog
Great idea Ross – why don’t you do it?
Frank can you help? He is making a valid suggestion and hoping your insight/experience and contacts would make this idea a reality. Ross is right, about your quick hands and non responsive support, why not help others in need, rather than just promoting products?
Frank,
Just wanted to let you know how inspired I am by your story. I know nothing about solar power yet but I’m quickly catching on.I think you are 100 % correct in reminding us all that it’s not just about the money I’m going to save but about the independence that I’m going to earn! My hope is to be completely self sufficient in one year I’m not